JP2002373680A - Fuel cell and method of gas supply in fuel cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce desired electric power and reduce size by effectively, using supply regions of fuel gas and oxidizing gas. SOLUTION: Separators 36 are formed and catalyst electrodes 32 and 33 are applied to opposite surfaces of an electrolyte membrane 31, in order that gas supply regions to which the separators 36 effectively supply fuel gas and oxidizing gas are inside the application regions of the catalyst electrodes 32 and 33 on the opposite surfaces of the electrolyte membrane 31, even under a manufacturing error and an assembly error. Generation of an electrochemical reaction in all regions of the gas supply regions can produce desired electric power from a fuel cell 20. Since electrochemical reaction can be generated in all regions of the gas supply regions, even under a manufacturing error and an assembly error, the separators 36 can be dimensionally reduced, and the fuel cell 20 can be made compact in size.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel cell and a gas supply method in a fuel cell, and more particularly, to an electrolyte membrane having a catalyst electrode carrying a catalyst applied on both sides thereof and a catalyst electrode on both sides of the electrolyte membrane. The present invention relates to a fuel cell including a gas supply member for supplying a fuel gas and an oxidizing gas, and a method for supplying a fuel gas and an oxidizing gas to a catalyst electrode in such a fuel cell.

[0002]

2. Description of the Related Art Conventionally, this type of fuel cell has an electrolyte membrane coated with a catalyst electrode carrying a catalyst on both sides, and supplies a fuel gas and an oxidizing gas to the catalyst electrodes on both sides of the electrolyte membrane. Have been proposed. In such a fuel cell, the flow path surface of the fuel gas or the oxidizing gas is designed so as to exactly coincide with the coated surface of the catalyst electrode in order to increase the efficiency. Some of the fuel cells with high efficiency have been developed for use in vehicles (see, for example, JP-A-2001-7).
No. 1753).

[0003]

However, in a fuel cell designed such that the flow surface of the fuel gas or the oxidizing gas exactly coincides with the coating surface of the catalyst electrode, the fuel supplied to the catalyst electrode can be sufficiently utilized. In some cases, it is not possible. Even if the flow path surface of the fuel gas or the oxidizing gas just coincides with the coated surface of the catalyst electrode due to design, the supplied fuel gas or the oxidizing gas may not be supplied to the catalyst electrode due to a manufacturing error or an assembly error. Power cannot be generated. In order to obtain the desired power, it is conceivable to increase the flow surface of the fuel gas or oxidizing gas with respect to the coating surface of the catalyst electrode. Would be unsuitable.

An object of the fuel cell and the gas supply method in the fuel cell of the present invention is to obtain a desired electric power by effectively using a fuel gas or oxidizing gas supply region.
Another object of the present invention is to provide a fuel cell and a gas supply method in the fuel cell, which aim at miniaturization of the fuel cell.

[0005]

Means for Solving the Problems and Actions and Effects Thereof The fuel cell of the present invention and the method for supplying gas in the fuel cell employ the following means in order to at least partially achieve the above object.

[0006] The fuel cell of the present invention comprises an electrolyte membrane having a catalyst electrode carrying a catalyst applied on both sides thereof, and a gas supply member for supplying a fuel gas and an oxidizing gas to the catalyst electrodes on both sides of the electrolyte membrane. In the fuel cell, the gas supply member is a member that supplies the fuel gas and the oxidizing gas to a region inside a coating region of the catalyst electrode applied to the electrolyte membrane.

In the fuel cell according to the present invention, since the fuel gas and the oxidizing gas are supplied to a region inside the coating region of the catalyst electrode coated on the electrolyte membrane, the supply region of the fuel gas and the oxidizing gas can be effectively used. To obtain the desired power. As a result, the outer peripheral dimension of the gas supply member can be reduced, so that the fuel cell can be downsized.

[0008] In the fuel cell of the present invention, the catalyst electrode is applied to the electrolyte membrane in a predetermined range of an outer peripheral portion of a supply region of the fuel gas and the oxidizing gas supplied by the gas supply member. It can also be. In the fuel cell according to the aspect of the present invention, the predetermined range is a range adjusted so that the fuel gas and the oxidizing gas are not supplied to the outer peripheral portion of the supply region even when a manufacturing error and / or an assembly error occurs. It can be. In this way, even if there is a manufacturing error of each member or an assembly error when assembling each member, the supply region of the fuel gas or the oxidizing gas can be used effectively.

In the fuel cell of the present invention, the gas supply member forms a fuel gas flow path with one surface of the electrolyte membrane, and supplies the fuel gas to a catalyst electrode applied to the one surface. A fuel gas supply member, and an oxidizing gas supply member that forms a flow path of the oxidizing gas by the other surface of the electrolyte membrane and supplies the oxidizing gas to the catalyst electrode applied to the other surface. You can also. In the fuel cell according to the aspect of the present invention, the fuel gas supply member includes:
The fuel gas is supplied in such a manner that the fuel gas supply region in which fuel gas can be supplied to one surface of the electrolyte membrane by the fuel gas flow path does not include a part of the application region of the catalyst electrode applied to the one surface. Is formed, and the oxidizing gas supply member is applied to the other surface in the oxidizing gas supply region where the oxidizing gas can be supplied to the other surface of the electrolyte membrane by the oxidizing gas flow channel. The oxidizing gas flow path may be formed so as not to include a part of the application region of the catalyst electrode.

A method for supplying gas in a fuel cell according to the present invention comprises an electrolyte membrane having a catalyst electrode carrying a catalyst applied on both sides thereof, and supplying a fuel gas and an oxidizing gas to the catalyst electrodes on both sides of the electrolyte membrane. A method for supplying the fuel gas and the oxidizing gas to the catalyst electrode in a fuel cell receiving and generating power, wherein the fuel gas and the oxidizing gas are provided in a region inside a coating region of the catalyst electrode applied to the electrolyte membrane. The point is to supply.

According to the gas supply method for a fuel cell of the present invention, the fuel gas and the oxidizing gas are supplied to a region inside the coating region of the catalyst electrode applied to the electrolyte membrane. A desired power can be obtained by effectively using the supply area. As a result, the size of the fuel cell can be reduced.

[0012]

Next, embodiments of the present invention will be described with reference to examples. FIG. 1 is a configuration diagram schematically showing a configuration of a unit cell 30 constituting a polymer electrolyte fuel cell 20 according to one embodiment of the present invention. The fuel cell 20 of the embodiment is configured by stacking a plurality of unit cells 30.

As shown in the figure, the unit cell 30 of the embodiment comprises an electrolyte membrane 3 having good proton conductivity in a wet state.
1, a catalyst electrode 32 applied to both sides of the electrolyte membrane 31,
33, and gas diffusion electrodes 34, disposed on both sides of the catalyst electrodes 32, 33 to supply fuel gas or oxidizing gas to the catalyst electrodes.
35, and a separator 36 forming a fuel gas flow path 37 and an oxidizing gas flow path 38, which are flow paths for fuel gas and oxidizing gas, by the gas diffusion electrodes 34 and 35, and forming a partition wall of the adjacent unit cell 30. . The material of each member is a material used for a normal polymer electrolyte fuel cell, and does not form a core of the present invention, and thus a detailed description thereof will be omitted.

As shown in the figure, the separator 36 has a fuel gas passage 3 formed by the gas diffusion electrodes 34 and 35.
The fuel gas and the oxidizing gas can be supplied to the catalyst electrodes 32 and 33 applied to the electrolyte membrane 31 by the oxidizing gas flow path 38 and the oxidizing gas flow path 38. Catalyst electrode 3 of electrolyte membrane 31
FIG. 2 shows the relationship between the application areas 2 and 33 and the gas supply area where the fuel gas and the oxidizing gas are effectively supplied by the fuel gas flow path 37 and the oxidizing gas flow path 38. In the drawing, a range A indicated by a solid line is an application region of the catalyst electrodes 32 and 33, and a range B indicated by a broken line is a gas supply region. As shown in the figure, the application regions of the catalyst electrodes 32 and 33 are coated with the catalyst electrodes 32 and 33 so as to include all of the gas supply regions, so that power can be generated by an electrochemical reaction in all the regions of the gas supply regions. Has become. Therefore, even if there is a manufacturing error in each part constituting the unit cell 30 or an assembling error generated when assembling the unit cell 30, an electrochemical reaction can be effectively generated in the entire gas supply region. The distance d shown in FIG. 2 as the area difference between the application area A of the catalyst electrodes 32 and 33 and the gas supply area B is such that the electrochemical reaction is effective in all of the gas supply areas due to manufacturing errors and assembly errors. May be set as the length that can occur, and is determined by the allowable range of the manufacturing error and the assembly accuracy.

According to the fuel cell 20 of the embodiment described above, an electrochemical reaction can be caused in all regions of the gas supply region for supplying the fuel gas and the oxidizing gas. Obtainable. Moreover,
Since an electrochemical reaction can be caused in all regions of the gas supply region by a manufacturing error or an assembly error, it is necessary to consider a manufacturing error or an assembly error for the dimensions of the separator 36 in order to obtain a desired power. Alternatively, the size of the separator 36 can be reduced.
Therefore, the size of the fuel cell 20 can be reduced.

In the fuel cell 20 of the embodiment, the catalyst electrode 3
The unit cell 30 is composed of the electrolyte membrane 31 coated on both sides with the gas diffusion electrodes 34, 35, and the separator 36, but the fuel gas is directly supplied to the catalyst electrodes 32, 33 without using the gas diffusion electrodes 34, 35. Or an oxidizing gas may be supplied. Even in this case, the catalyst electrodes 32 and 33 may be applied to both surfaces of the electrolyte membrane 31 and the separator 36 may be formed so that the electrochemical reaction occurs in all regions of the gas supply region for supplying the fuel gas and the oxidizing gas.

The embodiments of the present invention have been described with reference to the embodiments. However, the present invention is not limited to these embodiments, and various embodiments may be made without departing from the gist of the present invention. Of course, it can be carried out.

[Brief description of the drawings]

FIG. 1 is a configuration diagram schematically showing a configuration of a unit cell 30 constituting a polymer electrolyte fuel cell 20 according to one embodiment of the present invention.

FIG. 2 shows an example of a relationship between an application area of catalyst electrodes 32 and 33 of an electrolyte membrane 31 and a gas supply area where a fuel gas and an oxidizing gas are effectively supplied by a fuel gas channel 37 and an oxidizing gas channel 38. FIG.

[Explanation of symbols]

20 fuel cell, 30 unit cell, 31 electrolyte membrane, 3
2,33 catalyst electrode, 34,35 gas diffusion electrode, 36
Separator, 37 fuel gas flow path, 38 oxidizing gas flow path.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor ▲ Takahashi Tsuyoshi Hashi 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation (72) Inventor Toshiyuki 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Stock In-company (72) Inventor Mitsue Hibino 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation (72) Inventor Yasuyuki Asai 1 Toyota Town Toyota City, Aichi Prefecture Inside Toyota Motor Corporation (72) Inventor Soh Renewed 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation (72) Inventor Mikio Wada 1 Toyota Town Toyota City, Aichi Prefecture Inside Toyota Motor Corporation (72) Inventor Tsutomu Ochi Toyota Town, Toyota City, Aichi Prefecture No. 1 Toyota Motor Corporation (72) Inventor Katsuhiro Kajio 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor (72) Inventor Haruhisa Niimi 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Corporation F-term (reference) 5H026 AA06 BB03 CC10 CX05

Claims (6)

[Claims] 1. A fuel cell comprising: an electrolyte membrane having a catalyst electrode carrying a catalyst applied on both sides thereof; and a gas supply member for supplying a fuel gas and an oxidizing gas to the catalyst electrodes on both sides of the electrolyte membrane. The fuel cell, wherein the gas supply member is a member that supplies the fuel gas and the oxidizing gas to an area inside an application area of the catalyst electrode applied to the electrolyte membrane. 2. The catalyst electrode according to claim 1, wherein the electrolyte electrode is applied to a predetermined area of an outer peripheral portion of a supply region of the fuel gas and the oxidizing gas supplied by the gas supply member. Fuel cell. 3. The predetermined range is a range adjusted so that the fuel gas and the oxidizing gas are not supplied to an outer peripheral portion of the supply region even if a manufacturing error and / or an assembly error occurs. Fuel cell. 4. A fuel gas supply member, comprising: a fuel gas flow path formed by one surface of the electrolyte membrane; and a fuel gas supply member configured to supply the fuel gas to a catalyst electrode applied to the one surface. 4. An oxidizing gas supply member, which forms an oxidizing gas flow path with the other surface of the electrolyte membrane and supplies the oxidizing gas to a catalyst electrode applied to the other surface. The fuel cell as described. 5. The fuel cell according to claim 4, wherein the fuel gas supply member is provided in a fuel gas supply region where the fuel gas can be supplied to one surface of the electrolyte membrane by the fuel gas flow path. The fuel gas flow path is formed so as not to include a part of the application area of the catalyst electrode applied to one surface, and the oxidizing gas supply member is configured to have a flow path of the oxidizing gas for the electrolyte membrane. A fuel cell in which the oxidizing gas flow path is formed such that the oxidizing gas supply region capable of supplying the oxidizing gas to the other surface does not include a part of the application region of the catalyst electrode applied to the other surface. 6. A fuel cell in a fuel cell, comprising: an electrolyte membrane coated on both sides with a catalyst electrode carrying a catalyst; and supplying fuel gas and oxidizing gas to the catalyst electrodes on both sides of the electrolyte membrane to generate power. And a method of supplying the oxidizing gas to the catalyst electrode, wherein the fuel gas and the oxidizing gas are supplied to a region inside a coating region of the catalyst electrode applied to the electrolyte membrane.